The semiconductor industry has progressed into nanometer technology process nodes in pursuit of higher device density, higher performance, and lower cost. Despite groundbreaking advances in materials and fabrication, scaling planar device such as the conventional MOSFET has proven challenging. To overcome these challenges, circuit designers look to novel structures to deliver improved performance. One avenue of inquiry is the development of three-dimensional designs, such as a fin-like field effect transistor (FinFET). A FinFET can be thought of as a typical planar device extruded out of a substrate and into the gate. A typical FinFET is fabricated with a thin “fin” (or fin structure) extending up from a substrate. The channel of the FET is formed in this vertical fin, and a gate is provided over (e.g., wrapping around) the channel region of the fin. Wrapping the gate around the fin increases the contact area between the channel region and the gate and allows the gate to control the channel from multiple sides. This can be leveraged in a number of way, and in some applications, FinFETs provide reduced short channel effects, reduced leakage, and higher current flow. In other words, they may be faster, smaller, and more efficient than planar devices.
However, because of the complexity inherent in FinFETs and other nonplanar devices, a number of techniques used in manufacturing planar transistors are not well suited to fabricating nonplanar devices. As merely one example, conventional techniques for forming a compound semiconductor channel on an elementary semiconductor substrate may produce undesirable channel strains and/or lattice defects because of the different lattice structures of the different types of semiconductors. Likewise, conventional techniques are unable to effectively form a compound semiconductor oxide or other insulating feature between the channel region and the substrate. Therefore, while existing fabrication techniques have been generally adequate for planar devices, in order to continue to meet ever-increasing design requirements, further advances are needed.